Printing roller



y 7, 1937. A. 1.. FREEDLANDER 2,

Filed May 12, 1934 alum ABRAHAM I. FREED NDER,

Patented July 27, 1937 PRINTING ROLLER Abraham L. Freedlander, Dayton,Ohio, assignor to The Dayton Rubber Manufacturing Company, Dayton, Ohio,a corporation of Ohio Application May 12, 1934, Serial No. 725,399

3 Claims.

My invention relates to printing rollers and the method of making them.

It is the object of my invention to provide a printing roller that isresilient and that has a hard smooth impervious surface which is notaffected by acids, inks, or any other conditions incident to printing.

It is the particular object of my invention to provide a printing rollerwhich is not only resistant to ink, acids and other chemicals but whichwill have the exact amount of tack and will have this tack immediatelyupon being put into operation. The driers in the ink tend to destroythis tack.

It is the object of this invention to provide a renewable coating whichhas a marked afiinity for the surface of the printing roller, which willimmediately give the surface of the roller the desired tack while at thesame time provide the benefit of a resilient core and a hard smoothimpervious surface which is not affected by acids, inks and any otherconditions incident to printmg.

The surface must be a very uniform glass-like surface. The coating mustflow readily and have a marked afiinity for the material to which it isapplied, and the result must be a uniform tack. Furthermore, it must bepossible, as a part of this invention, for the tack to be retained untilthe coating wears oif. The coating must be resistant to repeatedwashings by kerosene for the cleaning of the rollers.

It is a further object to provide for the renewing of the rollers byapplying a new coating on the surface.

It is an object to provide for the application of such a coating in sucha manner that it may be uniformly applied and drys almost instantly.

It is my object to provide a surface that will not be affected by oilsnor by changes of temperature and humidity.

It is a further object to provide a surface which has the function ofevenly and satisfactorily spreading the ink materials.

It is a further object to provide a method of manufacture by which allnecessity for grinding the surface of the roller to finish it iseliminated and a roller, upon cleaning, can be renewed to its originalcondition without grinding or applying a new finish.

It is my object to provide a method by which the printing rollerincluding its cover are cured in such a manner asto eliminate thenecessity for a mold and they can be cured independently preferably bysuspension in hot water under pressure.

It is my object to provide a soft inker roller having a hard impervioussurface.

Driers and chemicals in ink cause a rubber roller to disintegrate invarious ways.

The driers (Cl. ill-67.8)

cause the ink to dry or cake on the rollers. Frequently, the lint flyingaround in the press room tends to gather on the surface of the rollerand increases this incrustation. Consequently, the rollers are washedafter each run, usually with kerosene, gasoline or benzol. All of theseliquids are harmful to rubber but the washing operation is essential toprinting.

If the rollers do not wash up quickly, they are defective because itmeans that the surface of the rollers is being attacked.

A satisfactory printing roller must be one that has the right amount oftack and retains it. This tack is essential to the successful operationof the printing roller. If there is too much tack, the result is ablurred printing accompanied by ink throwing. If there is not enoughtack, the rollers do not hold the ink and the result of printing is alsounsatisfactory. The roller surface must be tough enough because therollers are pressed against the irregular metal surface of the type.

Colored inks usually contain the maximum of drying materials becausethey are used on a higher class of printing with the better grade ofsmoother and harder papers. In view of the increase in color printing,these driers are becoming of increasing destructive effect on thesurface of rubber rollers heretofore employed and these driers destroythe important tack of the roller surface. The roller must be soft so asto accommodate the irregularities in the type, allow accurateadjustments and take up the load on the bearing supporting the axles ofthe rollers.

By the present invention not only is the surface secured with the properamount of tack while maintaining a tough hard smooth finish required,but it is possible to replace the thin cover coating of this inventionon the soft rubber core, thereby making it possible to renew the surfacewith the minimum of expense while preserving the maximum performance ofthe rollers.

It will be understood that these rollers are adaptable not only for theapplication of inks but also of printing varnishes and adaptable for usein graining machines in order to impart imitation grain effects on metalor cheaper woods giving the appearance of expensive woods. Such rollersare also applicable in such industries as the oil cloth, wax paperprinting and allied in-' dustries.

This problem of tack is most acute in the final rollers that pressagainst the type. It is less acute in connection with the distributorrollers which distribute the ink and the intermediate rollers betweenthe ductor or fountain rollers and the forming rollers. The formingrollers are the final rollers that press against the type.

Referring to the drawing: Figure 1 is a perspective of the roller;

Figure 2 is a section on the line 22 of Figure 1.

Referring to the drawing in detail, I is a steel axle for the resultingprinting roller which is to be manufactured by the hereinafter describedprocess.

Assuming this axle has had dirt and grease removed from it and there isno composition on the surface of the axle, the ends of the axle aretaped. The portion left exposed is that portion. on which the roller isto be mounted. The taped portion is that portion which will be supportedby the hearings in a printing machine in which the roller will beultimately mounted. The untaped portion is subjected to sand blasting togive the metal a clean surface for adhesion to hard rubber. As analternative to hard rubber adhesion, these metal axles or cores can bepickled or electrolytically cleaned and then brass or copper plated. Inthe latter event, the use of hard rubber would be eliminated and thesoft rubber of the roller would be attached directly to the brass orcopper plate.

Assuming that the metal rod is sand blasted, after sand blasting, therods are wrapped in clean paper until ready to be cemented. They aremaintained in a warm dry place until ready for the cementing operation.

The cement is made by dissolving hard rubber base stock in benzol in theproportion of one pound of hard rubber base stock to one gallon ofbenzol.

The metal axle or core is given two coatings of this cement. The cementis allowed to dry thoroughly before applying the hard rubber base stock.

In the drawing, 2 indicates the sand blasted surface and 3 the cement.

After the cement has thoroughly dried, the hard rubber base stock 4 isapplied comprising two ply, which is wrapped around the core. Thisprocess is usually carried out in a roller-building machine so as to laythe stock evenly on the core and eliminate any trapped air. Afterapplying the hard rubber to the metal axle, the surface of the hardrubber is treated with benzol, brushed and then allowed to dry.

Thereafter, the soft rubber base stock 5 is applied to the axle coveredwith the hard rubber. This stock is calendered single ply and is appliedso that the calender grain is in the direction of the length of theroller. The sheets of calendered stock are preferably attached to eachother with an eighth of an inch overlap. The roller is built up to theproper size allowing about onehalf inch excess in diameter for sag,grinding and polishing. The edges of the roller are trimmed beforecuring and a single jacket liner wrapped around the roll. The buildingup of the soft base stock from the calendered sheets is best performedin a roller-building machine. sulting product is submerged in acontainer of hot water under pressure and is kept there sufficientlylong to effect a curing. The approximate temperature of the water is250-260, and the pressure is 150-200 lbs. The approximate period of timefor a roller to be kept in the water is 3-6 hours.

Now turning aside from the provision of the yielding base, we turn tothe manufacture of the cover 6 for that base. The cover comprises a Acover tube made from calendered stock of a ma- The renot hitherto beenemployed but can be employed when the principle is understood of theirapplication and the method of their application is suitably taught as Iset forth herein.

For instance, the material divinyl acetylene which results from thevinyl derivatives of acetylene is prepared by reacting acetylene in thepresence of a non-alkali catalyst comprising cuprous chloride. Anon-benzenoid polymer of acetylene having the emperical formula CaHa maybe employed. A pre-formed drying oil which is a liquid, non-volatilepolymerization product of acetylene may be used. This rubber-likematerial may be referred to briefly as a class of material as a divinylacetylene polymer. Insorprene on standing passes slowly into an elasticsolid having the chemical composition and many of the chemical reactionsof rubber but is resistant to the attack of oils and acids. I alsodesire to comprehend the use of polymethylene-sulfide, a polysulfidereaction product. I also comprehend the use of a plastic polymerchloroprene (reaction product of monovinylacetylene and hydrochloridacid); or polychloroprene and polybromoprene.

After this stock is calendered two-ply .075 ga. finished thickness, thetube is made by cutting to the proper width and by making a butt splice.The spliced seam is protected by a small strip of frictioned fabric toprevent the seam from opening up when the tube is blown on to themandrel. When the tube is thus made, it is mounted on a metal mandrel bybeing inflated and, while inflated, slipped on to the mandrel. Themandrel is sherardized or plated in any manner desired to give thesurface desired. The inflation is effected by the use of compressed air.After the tube is mounted on the mandrel, it is wrapped down with one ormore layers of wet jacket liner.

The cover tube thus prepared is suspended in hot water under pressurewith the same approximate temperature and pressure as indicatedheretofore for the curing of the roller.

The cured tube is thereafter removed from the mandrel and the outsidesurface, as the tube exists before removal from the mandrel, is sanded.Thereafter, two coats of low temperature curing cement are applied tothe ground surface of the roller, the making of which has already beendescribed. Similar coats of cement are applied to the sanded surface ofthe tube.

The sanded surface of the tube is now turned to become the inside of thetube. When the cement is sufliciently dry, the cover tube is blown on tothe roller by compressed air which inflates it so that it can be slippedover the relatively soft rubber roller. This presents the outside of thecover tube with a mirror-like, tough, smooth surface on the outside. Itwas such surface that was in engagement with the mandrel on which thecover tube was cured. The cover is then cured to the base stockcomprising the soft rubber roller in hot air under pressure for thenecessary time. The ends of the cover are attached to the grooved endsof the core or soft rubber roller by means of cord and tape or cord, inkand oil-resisting flexible bands. The ends are trimmed and lacquered togive a finished appearance.

Cement tack coating I make the cement tack coating 1 by employing benzolor any other suitable vehicle in combination with the foregoingsynthetic materials mentioned in this application.

The proportions can be varied according to the viscosity desired, butthe viscosity should be such that the roller can be dipped in a bath ofthe cement, tvvirled in the bath and then removed, whereupon the cementdrys almost instantly and the roller ready for use in a few minutes.

This cement has an extraordinary ailinity for the surface of the sleeve6 that constitutes the outer part of the roller 5. It is possible towash this outer surface of the roller repeatedly without disturbing thecement.

Futhermore, this cement is of broader application than the particularform of roller shown in the drawing herein as it can be applied to anyordinary rubber roller and thereby give to that roller ink resistingproperties which are closely akin to those pictured in the presentapplication. But not, of course, as perfect in result.

I have also found it to be helpful under certain conditions to treat therollers with chemicals which have the effect of tending to open up thepores of the rubber or the synthetic compound constituting the layer 6of the roller and then I apply the cement so as to get a better adhesionof the cement to the surface of the roller.

This cement can be applied to the uncured or unvulcanized surface of theroller. Then by slipping the sleeve on the mandrel for vulcanizing itwill still retain its tacky surface. Another use for this cement is thatof a varnish. In using it as a varnish on existing rubber rollers it ispossible to get the exact amount of tack and also to some degree theresistance to oils, driers and other chemicals associated with ink. Thedifiiculty with a rubber roller having this cement is that it would nothave the same hard impervious surface nor would the roller be nearly assoft as that of the instant application.

It will be understood that this cement is applicable not only to rollersbut to any other types of surfaces having similar purposes and similarconstruction.

By the utilization of this oil-proof cover stock of the specialcompositions hereinbefore indicated, it is possible to get all theresiliency of rubber without the disadvantage of disintegration by inksor oil to which rubber is subject.

All the advantages of rubber with a tough, smooth, impervious surfaceare secured on the cover together with the advantages of resiliencywhile, at the same time, the disintegration of the cover does not occuras when made with rubber which is subjected to the oils, driers,solvents and acids occurring in modern printing processes.

It will be understood that I comprehend within non-rubber materials bothnatural and synthetic materials and compounds which have the propertiesof resiliency, can have imparted to their surface an imperviouscondition and which are inert to inks, oils, driers, solvents, acids andtemperature and moisture conditions, particularly those conditions metin printing. The compounds mentioned for this purpose have peculiarproperties not found in rubber of resisting over long periods the actionof such material and conditions which would deteriorate rubher.

It will be further understood that the hot water and air vulcanizingprocesses or their. equivalent are comprehended within my invention, andany similar process is comprehended which will produce a homogeneoussoft product Which removes the trapped air between the plies. andresults in a soft, velvety product.

It will be further understood that a cement for cementing the sleeve onto the base roller should preferably be of such a character that it willpermit the easy removal of the sleeve by heating at from degrees todegrees Fahrenheit so that the sleeve pulls oiT easily at suchtemperature while sticking firmly at ordinary working temperatures.

I find that in very long rollers it is sometimes desirable to grind orpolish the surface of the sleeve about .020 which trues the roller up toa point within .001 of an inch. The material of this sleeve permits thegrinding of a very smooth surface if it becomes necessary to grind toreduce the size.

I further find that an initial tack can be imparted to the surface ofthe rollers if desired and the amount of tack controlled by the initialtreatment if the surface of the roller is treated with rosin oil, andallowed to stand for 24 hours after having been slightly heated.

Instead of benzol, gasoline or kerosene, or a mixture of both may beused. When I refer to benzol it will be understood that thesealternative products or a combination of them, or the equivalentthereof, may be substituted for benzol.

It will also be understood that I desire to comprehend within myinvention such modifications as may be necessary to adapt it to varyingconditions and uses.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent, is:

1. A new article of manufacture for use as a printing roller comprisingan axle of metal, a coating thereon to which rubber adheres, a softrubber roller body vulcanized to said coating, a relatively thin coatingof non-rubber material adapted to protect the rubber within while at thesame time presenting a hard impervious surface that is not affected byprinting inks, and a cement coating of benzol and divinyl acetylene.

2. A new article of manufacture for use as a printing roller comprisingan u axle ofhmgal, ,a

.coatingthereont which ruloierildlgeres, a softf rubbenlillfi!"bodylulc'aniz W said coating, a relatively thifcgatjpg on;bberllniiaterialadapted lp protecttheiubbeg withi'fi'fihile at the sametime presenting a hard impervious surface that is not afiected byprinting inks said coating being capable of vulcanization to the softrubber within, and a cement coating comprising a solvent such as benzoland isoprene.

3. In combination in a printing roller ofa vulcanized annular rubberroller, a resilient sheath of synthetic rubber that is resistant to oiland chemicals and ink mounted on the annular body roller, said sheathhaving an exterior surface formed during vulcanization that is hard,smooth and impervious, and a cement coating on the exterior of thesheath to impart tack, said cement comprising a solvent such as benzoland a synthetic rubber such as divinyl acetylene.

ABRAHAM L. FREEDLANDER.

